Method of preparing resin compositions

ABSTRACT

Polyphenylene resin compositions of fused and non-fused aromatic ring compounds containing an aromatic curing agent in combination with other resinous modifying and forming material, with or without insoluble polymers, and method.

Waited States Patent 1 Eilow 1451 Sept. 11, 1973 METHOD OF PREPARINGRESIN COMPOSITIONS [56] References Cited [75] Inventor: Norman Bilow,Los Angeles, Calif. UNITED STATES PATENTS 73 Assignee; Hughes Ai ftCompany, Culver 3,555,108 l/l97l Bilow et al 260/823 City, Calif.Primary Examiner-Theodore Morris [22] 1971 A!t0rneyW. H. MacAllister, Jrand Alton V.

Appl. No.: 194,779

Related US. Application Data Continuation-impart of Ser. No. 665,284,Sept. 5, 1967, abandoned.

US. Cl 260/823, 106/274, 106/275,

260/2 H, 260/28.5 AS Int. Cl C08g 49/04 Field of Search 260/2 H, 28,28.5,

Oberholtzer [57] ABSTRACT 9 Claims, No Drawings METHOD OF PREPARINGRESIN COMPOSITIONS This application is a continuationin-Part of Ser. No.665,284, filed Sept. 5, 1967, now abandoned.

The invention herein described was made in the course of or under acontract or subcontract thereunder with the Department of the Navy.

The present invention relates to a discovery of the method of preparingcurable fusible and soluble composite aromatic resinous compositionsincluding modifications thereof and particularly aromatic polymers offused and unfused ring polyphenylene material fusible and soluble inhalogenated solvents and curing agent combination containing modified ormodifying constituent material with or without intractable polymers ofpolynuclear aromatic resins, and the products thereof. Moreparticularly, this discovery relates to and is exemplified by modifyingsoluble aromatic polymers, polyphenylene polymers of biphenyl,terphenyls, isomers thereof, and mixtures of said compounds for use inthe preparation of powder, liquid, and plastic resin compositions forcoatings, laminations, or in forming molded structures of high strengthand high thermal stability, including modifications thereof. In manyinstances, the prior art. resins have been entirely unsuitable for thepurpose of making laminated, or molded structures, or for protectivecoatings having high thermal stability. The reason for thisunsuitability is that the prior art resins have either been of lowmolecular weight and consequently have had low fusion or softeningpoints and poor thermal stability, or they have been substantiallyinfusible and insoluble in organic solvents, or they have not been knownto be capable of thermosetting. 1n the case of low molecular weightproducts of the prior art, no means had previously been available tocure these materials and convert them into useful infusible andinsoluble products during fabrication. In other words, many of the priorart low molecular weight resins, remained permanently fusible. It hasalso been known to the art that infusible, insoluble, intractable,resinous material has formerly been comparatively useless forthermosetting fabrication.

The insoluble and infusible prior art resins could not be fabricated orotherwise utilized because fabrication requires that the resinousmaterial flow and thermoset to take the shape of a mold, or to flowsufficiently to become a homogeneous binder, or to be soluble in asolvent so that fillers, or fibers can be coated orthat lacquers can beprepared therewith.

Further, some of the prior art fusible phenylene polymers owed theirfusibility to the presence of aliphatic groups such as alkyl groups orolefinic groupsin the polymer. Often these aliphatic groups were formedduring the course of a polymerization and the reduced polymer thus hascarbonzhydrogen ratiosof significantly less than 1.4.

Completely para-polyphenylenes have been obtained by severalinvestigators and molecular weights were reported to be as high as'5,000to 10,000. Completely para polymers are, however, entirely infusible andrelatively insoluble in conventional solvent material. Infusibility of aphenylene polymer almost always occurs ture allows. The new disclosureherein now provides a method of use and application for such relativelyinsoluble polymers.

Further illustrative of the insoluble and intractable polymers ofpolyphenylenes were those obtained from the hot solvent extractedpolymers as derived from the following runs as disclosed in the aboveindicated patent application.

EXAMPLE A A mixture of m-terphenyl (230 g., 1.0 mole), biphenyl (77'g.,0.5 mold), benzene (55 g., .7 mole), and anhydrous cupric chloride (807g., 6.0 mole) is prepared and heated to 165C in an oil bath. Whilestirring continuously anhydrous aluminum chloride (187 g.) is graduallyadded to the reaction mixture over a 2-hour period. The mixture is thencooled, pulverized, and additional aluminum chloride (67 g.) is added.It is then reheated at 165C for an additional 45 minutes.

The crude polymer is thoroughly cleaned by trea- -ment with concentratedhydrochloric acid, 6 N hydro- EXAMPLE B A mixture of ortho-terphenyl(200 g., 0.87 mole) and anhydrous cupric chloride (234 g., 1.74 mole)was heated to C while stirring continuously. Anhydrous aluminum chloride(116 g.) was added periodically over a two-hour period while maintainingthe temperature at 150 10C. Additional cupric chloride (1 17 g., 0.87mole) was then added in portions over the next three'hours whilemaintaining the temperature at 1 10C. Upon completion of the-reaction,the crude product was thoroughly washed with concentrated hydrochloricacid, then diluteacid, and finally water. After drying, the crudepolymer was continuously extracted with boiling benzene in a Soxhletextractor for 4 days. This procedure removes low molecular weightproducts. After completion of the benzene extraction, the crudepolymer-was continuously extracted with boiling 1,2,4-trichlorobenzene.That polymer fraction which was soluble in the trichlorobenzeneweighed-67 grams (33 percent yield) and melted at The nonextractablepolymers are the by-product nonsoluble polymers. I

Prior art polyphenylene resins have also been produced from Wurtz-Fittigand other synthesis proceeanytime a polymer chain segment occurs inwhich there are more than eight or-nine phenylenegroups linked in Y thepara position. As a consequence, fusible parapolyphenylenes of highmolecular weight cannot be obtained. This is theoretically due to theextremely strong van der Waals forces which the linear molecularstrucdures from nitrogen-containing aromatic compounds through reactionssuch as diazotizations or nitrosations.

Resinsand polymers of thesetypes invariably contain tures of fusiblepolyphenylenes and curing agent therefor, as herein provided.

For many applications in the art of molding and fabricating structureshaving high thermal stability, it is essential to use ahigh-temperature-stable polymer which has an intrinsically highmolecular weight or which may be cross-linked, cured, vulcanized, andthe like, to produce a high molecular weight (or an infinite molecularweight) during the said molding and fabrication process. At the sametime, it is essential that the polymer be fusible or capable of flowunder the conditions of heat and pressure that are used in the saidmolding and fabrication process and that the uncured polymer be solublein suitable solvents so that fillers, fibers and the like can beintimately coated with the polymer mixture prior to the said molding andfabrication process.

The otherwise intractable and infusible higher polymeric polyphenylenesand the like can now be used to obtain thermosetting compositions whenthey are mixed with the curable polyphenylene polymers, as embodiedherein. Mixtures may be prepared in any proportion desired, dependentupon the relative hardness and molding parameters desired. Further, themixtures, as herein contemplated and depicted can be made useful incommercial thermosetting application with fusible and tractablethermosetting polyphenylene polymers and curing agent therefor, toconvert the mixture into useful infusible and insoluble products duringthermosetting fabrication.

In. a copending application disclosure, Ser. No. 349,770 (nowabandoned), and replaced by applications Ser. Nos. 665,262, nowabandoned, 665,303, now abandoned, and 665,308, now U.S. Pat. No.3,595,811, there are disclosed soluble and tractable polyphenylenepolymers and method of production thereof, including the preparation ofcomposite resin compositions therefrom which are curable and areutilizable in the uncured state herein. The fusible and solublephenylene polymers disclosed therein, including the soluble and fusiblepolyphenylenes disclosed in the continuationin-part applicationentitled, Commercially Useful Polyphenylene Polymers and Method ofProduction Thereof, Ser. No. 665,262, cofiled herewith in coinventorshipwith Leroy J. Miller, are applicable herein in providing the soluble andtractable polyphenylene polymers of the character desirably utilizedherein. Further, curable composite mixed or modified polyphenylene resincompositions may be prepared by incorporating the modifying or modifiermaterial with the soluble and fusible curable compositions obtained bythe process of the copending application Method of Providing UsefulHeavsetting Aromatic Polymer Resinous Compositions and Products, Ser.No. 665,578, now U.S. Pat No. 3,555,108, in which I am co-inventor withLeroy J. Miller, included herein by reference thereto. The infusible,insoluble phenylene polymers produced by the above method werepreferably separated in the said disclosure, or not otherwise utilizableby any other method known to the art to produce fabricated structures byconventional molding or coating and laminating techniques. The discoverythat comparatively insoluble and infusible polyphenylenes can now beusefully utilized, including the advantages of improving upon thethermosetting character of the thermoplastic material and the methodtherefor is the primary purpose of this new disclosure.

It is very important that the soluble and fusible branched polyphenyleneresins of the present invention be produced by an overall process asdisclosed herein and in the above application. The materials andprocessing therein and in the continuation application thereof, areincorporated herein by reference thereto. This provides for productswhich are essentially fully aromatic, fusible and tractablepolyphenylene polymers with no significant production of intractable andinfusible polymers, or, amount of reduced ring character.

a. However, in the event that the addition of more or less significantamounts of one or more of the infusible and intractable polymers, orother material as indicated, are desired to be added, or be incidentallyor natrually occuring* (*In explanation, it should be pointed out thatif the intractable polymer was formed during the preparation of thefusible and soluble polyphenylene, the amount of intractable polymerwhich can be left therein is quite limited. This is attributed to thefact that an intermediate fraction or polymer, with solubilityproperties between the soluble and intractable fractions is generallyformed simultaneously and this intermediate fraction can be swellable,but not actually soluble. This is why fractionation was being used.Thus, swelling occurs in lacquers and the melt-flow characteristics ofthe polymer are much poorer. When the intractable polyphenylene containsno solvent swellable phase it can be incorporated into the thermosettingpolyphenylene lacquerswithout producing the swelling effect and it thendoes not interfere with flow properties appreciably during fabrication.)with the soluble and fusible polyphenylenes, for subsequent curingtherewith, this may be accomplished by proper control of the componentrelationship, as indicated. The soluble and fusible polyphenylenepolymer compositions are also treated with a curing agent and partiallypolymerized with retention of solubility and subsequently provided as aredispersible and soluble resin or molding powder, in the mannerhereinafter described.

As indicated, the soluble and fusible, branched, fully aromaticpolyphenylenes useful in the present invention, have a meancarbonzhydrogen ratio of and about 1:5 being between 1:4 and 127,. butmore commonly being between L43 and 1.60, and. owe their fusibility andtractability to the presence'of phenyl, or biphenyl, and the like,branches as well as to a meandering configuration of their'longestchains. Because of the existence of these branches and meanderingconfiguration, the polymer molecule cannot attain a planar configurationas the completely para-polyphenylenes do and consequently close packingof the branched polymer molecules does not occur and the extremelystrong .van de Waals forces, which are present in the completely parapolymer, are not observed. The tractable (soluble) and fusiblepolyphenylene polymers are preferably provided herein by thepolymerization of biphenyl, terphnyls, quarterphenyls, branched isomersthereof, mixtures of the same, and mixtures of the same with phenyleneoligomers or polyphenyls with less than 5 aromatic rings, by the processas herein exemplified and more specifically described and exemplified inthe above application, incorporated herein by reference thereto.

The exceptional characteristics of the soluble and fusible branchedpolyphenylene resins of the present invention may be described in termsof four outstanding properties:

I. They have excellent thermal stability, exhibiting in the cured state,negligible weight loss between 400 500C in an inert atmosphere. 2. Theyhave mean molecular weights which range from about 500 up to 5,000 ormore and as preferably utilized herein a mean molecular weight of andabout 1,000 i 500.

3. They are sufficiently soluble in certain common organic solvents, andparticularly halogenated hydrocarbon solvents as the halobenzenes,di-halobenzenes, trihalobenzenes, trichloroethane, tetrachloroethane,chloroform, including toluene, and the like, especially when hot, topermit their use in lacquers and varnishes.

4. They are fusible and flow sufficiently at temperatures that areconventionally employed in hot molding presses to permit theirfabrication in conventionally available equipment.

This unique combination of properties, coupled with their ease ofpreparation in good yield, constitutes a significant and major advancein the state of the art of fully aromatic polyphenylene resins. Thisunque combination of properties is the direct result of the properchoice, and proportion of reactants andof the proper choice and use ofthe catalyst and oxidant. In the copending disclosure, Method ofProviding Useful Heat- Setting Aromatic Polymer Resinous Compositionsand Products, Ser. No. 665,578, are described unique polyphenylene resincombinations and compositions which utilize the soluble and fusiblebranched polyphenylene resins as components of curable, or vulcanizablecompositions which can be fabricated into useful coatings, molded andlaminated structures. Structures produced in this manner include;electrical insulators, rocket nozzles, and structural materials whichare required to withstand high temperatures, such as hyperthermalablative conditions, or substantially high temperatures for long periodsof time. Some commercial applications do not require the withstanding ofsuch harsh conditions, and whereas. it will be recognized that some ofthe herein modified polyphenylene composite resins may be likewiseapplicable, many of the essentially modified polyphenylene resinouscompositions embodied herein are otherwise suitable formany conventionalapplications providing improvement and extending applicable uses ofmaterials heretofore unavailable therefor.

I have now found that it is possible to fabricate, mold, and cure newcomposite resin material comprising the soluble, fusible branchedpolyphenylene resins which have heretofore been disclosed as moldableand curable with a curing agent therefor. As exemplified herein, suchcuring agent is an aromatic polymethylol, or derivative thereof,including an acid catalyst, effecting copolymerization or hardening ofthe polyphenylenes to an infusible and intractable useful resinousstate. The curing agent may be exemplified as a xylyleneglycol-p-toluenesulfonic acid telomer, or simply a mixture of thepolyphenylene polymers and curing agent material prepared in-situ, incombination, with or without, tractable and/or intractable modifyingmaterial. Thus, I can now retain and utilize intractable polynucleararomatic polymers such as para-polyphenylene or the intractablepolyphenylene polymers produced as a by-product of the soluble, fusible,branched polyphenylene synthesis, in the composition or added thereto.

l have found that the soluble, fusible polyphenylenes previouslydisclosed can function as a reactive flux such as to permit the use ofrelatively large amounts of intractable polynuclear aromatic resins inthe composite molding compositions of this invention to achieve goodflow, homogeneity and other essential molding characteristics, the wholecomposite molding compositions being brought to a state of cure by theapplication of heat, or heat and pressure in the presence of the curingagent. The presence of the comparatively insoluble polyphenylenematerial, or other additive, may be in various useful portions, fromminor to major, as desired to obtain the proper heat setting results andhardness desired.

l have unexpectedly found that although the polymethyol aromaticcompound-acid curing agent cannot bring about satisfactory cure of theintractable polynuclear aromatic resin, the composite resins comprisingthe intractable polynuclear aromatic polymers or resin and the soluble,fusible, branched polyphenylene resin can-be homogeneously cured by saidcuring agent in the same manner as said curing agent can cure the saidsoluble, fusible, brached polyphenylene resins above. I have furtherdiscovered that many of the heretofore thermoplastic resins and likematerial can be utilized with the thermosetting polyphenylene polymersto produce useful heatsetting compositions, with or without theinclusion of the insoluble polymeric material being present therein. Asthesoluble, fusible branched polyphenylene resins that may be'employedin the present invention, I may use any of the soluble, fusible branchedpolyphenylenes disclosed in Ser. No. 349,770 (now abandoned), and thecopending filed application, as indicated. The intractable polynucleararomatic polymers that may be employed in the present invention and thatare characterized by being substantially infusible and being insolublein those solvents such as halogenated benzene, p-dioxane, chloroform,tetrachloroethane, toluene, trichloroethane, trichloroethylene, and thelike, and particularly in heated or hot to boiling condition, in whichthe said soluble, fusible branched polyphenylenes are soluble.'Suchintractable polymers as parapolyphenylenes, or those by-productpolymers'which are substantially insoluble and infusible and separablefrom the soluble polymers, as de- "scribed herein and in the indicateddisclosures, may be added or inherently present in the soluble orfusible polymer mixtures.

As the curing agents that may be employed in the present invention, Imay use compositions of the character described in Ser. No. 349,770 (nowabandoned) and replaced by application Ser. No. 665,262, and applicationSer. No. 665,308, filed therewith, in which I am co-inventor with LeroyJ Miller, or polyfunctional aromatic sulfonyl halide material as hereindescribed and illustrated.

Illustrative of a base combination of polyphenylene polymers and curingagent in combinations with the intractable solids, which may beinherently present or added, is the following:

EXAMPLE 1 165C, to effect a fluid batch, and the oxidant was added insmall portions over about a l to 2 hour period. Mixing and heating wascontinued for a period of about 3% hours with the temperature maintainedbetween 135 180C. Preferably the crude product, after cooling, is groundto a powder and treated with hot concentrated hydrochloric acid (12 N)to remove the inorganic salts, by several washings, followed by severalwater washes. When cleaned, the solids are essentially soluble in asuitable solvent, for example, in hot to boiling halogenated solventmaterial of the character of the halobenzenes as chlorobenzene,bromobenzene, 1,2,4- trichlorobenzene, or chloroform, tetrachloroethane,and the like. This solution can be directly utilized herein. However, itis preferable to first extract the unreacted monomers, partially reactedmonomers and extremely low molecular weight oligomers by treatment andwashing with hot mixtures of naphtha and benzene or other suitablesolvent. Such extraction mixtures are applicable per se to the curingprocess herein, with or without the solids contained therein as hereinprovided, naturally occurring, or added, with the resultant curedproduct being of lesser stability to extremely high temperatures, butsatisfactory for some commercial useage. Further, although the residuetherefrom, resoluble in a suitable solvent therefor, and with or withoutsome insoluble polymers occuring therein, may be used herein, thepreferred polyphenylene polymers, of a molecular weight preferably onthe order of 1,000 i 500 and up to about 2,000 are those which areobtained by solvent extraction of the residue from the first extraction.Such further extraction is effected with a hot halogenated solvent astrichloroethylene, chlorobenzene, or 1,2,4-trichlorobenzene, and thelike, as disclosed in the co-pending application for Commerically UsefulPolyphenylene Polymers and Method of Production Thereof," Ser. No.665,262, filed by Leroy J. Miller and myself, and the soluble andinsoluble polyphenylene products therein, without removal therefrom areapplicable to the process herein, to provide useful products, asindicated.

The following examples are given to illustrate the preferred process andindicate its application and use in preparing products of the presentinvention, discovery and disclosure:

EXAMPLE 2 1 300 grams of polyphenylene polymers having a melting rangeof 160C 180C and a mean molecular weight of about 700 1,000 wasdissolved in600 ml. of trichloroethylene heated at its boiling point. Acuring agent solution was prepared from 150 grams of pxylyleneglycol, 45grams of p-toluenesulfonic acid hydrate, and 500 ml. of chloroform byrefluxing the components together for 20 hours while removing water inan azeotropic trap.

The polyphenylene solution and curing agent solution were mixed togetherand heated at reflux for20 hours. After cooling, part of the lacquer wasblended with para-polyphenylene in a high shear blended to yield aslurry containing approximately two parts of polyphenylenexylyleneglycol solids by weight to one part of parapolyphenylene by weight. Themixed lacquer was then used as a varnish to coat dry carbon cloth(HITCO, CCA-l) which was then air dried and subsequently vacuum dried at160F for ten minutes.

3 The pre-pregs" then contained 48 percent of polymer solids based onweight.

Twenty-one plies of "pre-preg" were then stacked and molded at 400F and500 psi for a period of two hours. The laminates then weighed 339 i 1gram and had 46 percent solids content. They were then postcured byheating for 18 hours at 275F, followed by a programmed heat cycle for108 hours with the temperature rising gradually from 275 550F, andfinally heated for six hours at 550F. Laminates were cooled to 200F inthe post-cure oven before removing. The cured laminates each weighed 332i 1 gram and contained 45 percent resin solids by weight. Theirdensities were 1.30 i 0.02. The cured laminates were homogeneous and theresinous binder therein had been converted into an insoluble andinfusiblematerial.

EXAMPLE 3 A branched polyphenylene-xylyleneglycol-para polyphenylenelacquer or varnish was prepared as in Example 2. The lacquer was thendried for 18 hours at ambient temperature then vacuum dried for minutesat F. The polymer mixture was then ground to a fine powder. 32 grams ofthe dried polymer was loaded into a press at 500F and was molded for twohours at a pressure of 3,000 p.s.i. The molded specimen weight 31.8grams. It was then post-cured, following the same procedure described inExample 2. The final weight was 30.3 grams. The final product wasdense,glossy and completely cured to an insoluble and infusible material.

EXAMPLE 4 A polyphenylene-xylylenglycol lacquer or varnish was preparedas in Example 2, except that an intractable polyphenylene other than.para-polyphenylene was used in place of para-polyphenylene. The lacquerwas then dried for 18 hours at ambient temperature then vacuum dried for105 minutes at 160F. The polymer mixture was then ground to a finepowder. 32 grams of the dried polymer was loaded into a press at 500Fand was molded for two hours at a pressure of 3,000 p.s.i. The moldedspecimen weighed 31.8 grams. It was then postcured following the sameprocedure described in Example 2. The final weight was 30.2 grams. Thefinal product was dense, glossy and completely cured to an insoluble andinfusible material.

From the above it will be recognized herein that the soluble and fusiblepolyphenylene polymers, as utilized herein, are polymers of polymerizedmonomers selected from the group consisting of biphenyl, orthoandmeta-terphenyls, the 2,2-, 3,3 2,3'-, 2 ,4-, 3,4'-, diphenyl biphenyls,the 1,2,3-, 1,2,4-, and 1,3,5- triphenylbenzenes, mixtures thereof, andmixtures thereof with other phenylene oligomers and polyphenyls with notmore than five aromatic rings.

With reference to such soluble and fusible polyphenylene polymers, amixture thereof can be prepared with the modifying or modified material,in a solvent or dry state, and the curing agent subsequently. added, ina solvent or dried'state. Initially, it may be desirable to mix thesoluble and fusible .polyphenylenes with the curing agent material andsubsequently adding the modifying or modified material, with the solubleand fusible polyphenylenes in an unreacted or partially reacted state,and in a dry or wet state. Whereas, for better homogeneity, thedescribed processingas described is preferred suitable and satisfactorycompositions for other or less stringent application may be obtained.Such mixtures preferably provide usable resinous compositions of solubleand fusible polyphenylenes having a carbon to hydrogen atomic ratiobetween 1.421 to l.7:l, a melting range of about 120 300C, and a meanmolecular weight range of 1,000i 500 to about 3,000 in combination withhigher molecular weight aromatic polymers of over 3,000 molecular weightand preferably in essentially fusible and soluble or dispersiblecombination with a thermosetting curing agent for said soluble andfusible polyphenylenes.

Although it is preferred to utilize the polyphenylene in polymer form,and the curing agent comprising an aromatic polymethylol material incombination with a polymerization catalyst in the prepolymer form, asabove described, the monomer combination of aromatic polymethylolmaterial and acid catalyst may be mixed with either the solublepolyphenylene polymers or the aromatic monomers forming said polymers,and reacted in-situ, with constant removal of water, to obtain aninferior but useable soluble product which can advantageously bemodified, as described herein, or used to modify a thermoplastic to athermosetting composition by admixture therewith in liquid, plastic, orpowder form. In addition to the otherwise relatively insoluble andinfusible aromatic resin-forming material as exemplified by the para andother polyphenylenes, such other modifying or modified materials assoluble or intractable and insoluble polymers of polyphenylene sulfide,polyphenylene oxide, Wurtz-Fittig type polyphenylenes, as known to theart and referenced in the herein noted Ellis publication, polyphenylenesfrom ble and insoluble, highly aromatic naturalor synthetically preparedtars or coal tar pitch, and other natural or synthetic resins aspolystyrene, 'terephenes, benzoin, vinyl compounds, resinamines, oramino resins, natural resins, and the like, or resin-formed materials ofarcmatic acids and esters, are applicable by, substitution, inproportion of the whole or in part, or in equivalent proportionalamounts of the indicated solids addition, to the soluble polyphenylenepolymermaterial and curing agent combination; With or without thepresence of such added or inherently present insoluble solids and othermodifying or modified material, as described when mixed with the fusibleand tractable polyphenylene polymers, care is necessarily taken tomaintain the solution or reaction phase between the soluble and fusiblepolyphenylene polymers and curing agent for subsequent heat curingthereof and solidification of the composite mixture. Such compositemixtures are directly useful, in solvent, powder, or plastic-form. Asindicated, the curable solution, fusible polyphenylene polymers andcuring agent compositions, as described, may be modified inincorporating various thermosetting or thermoplastic polymers, assynthetic rubbers, isobutene resins, polystyrene, and the like,including mixtures of modifier materials with or without the parapolyphenylene and the like solids in solution, dispersion or powder formtherewith, thus increasing the thermoplastic s resistance to heat andimproving the hardness and heat resistance of the thermoplastic orconversely reducing the hardness of the cured-polyphenylene compositiondependent upon the relative proportions of the modifier material addedto the solution or powder mix before heat setting.

The above additive polymers of synthetic; and natural occurrence arewell known to those of skill in the art as found in the background ofthousands of pages of literature found in the publications of Ellis onThe Chemislry of Synthetic Resins starting with Vol. 1 in I935,including thousands of cross-references to other literature and thelntra-Science publication of Brand, Rupt and lmmergut, Polymer Handbook,copyright 1966. As herein described, the aromatic natural or syntheticthermoplastic pitches and tars are usually polymer mixtures of biphenyl,terphenyl, quatraphenyl, hexaphenyl, and the like, compounds which maycontain some naphthylene, anthracene, phenanthracene, or homologues andsubstituted derivatives thereof in varying amounts dependent upon theorigin and source. Such materials are believed to be also reactive withthe curing agent material to convert the composite mixtures to athermoset state. Accordingly, such tars and pitches may be present inamounts from a small percent to over percent, and up to percent with aportion being polyphenylenes, upon care and selection for the resultsdesired. Such natural and synthetic polymer mixtures are commerciallyavailable as aromatic pitch or tar material and derived from naturalsources as oils, tar, coal and the like, or as synthetic products in thesynthesis of aromatic hydrocarbons.

The curing agent portion of the above typical composition is preferablya prepared prepolymer solution formed by reacting an aromaticnon-phanolic polymethylol compound with an acid catalyst preferably ofan aromatic character of one or more of the sulfonic acids, asp-toluenesulfonic acid, benzenesulfonic acid, cyclohexane-sulfonic acid,and mixtures thereof, including mixtures with less preferred acids. Lesspreferably, there may be employed such acids as phosphoric acids,alkylphosphonic acids, arylphosphonic acids, alkylphosphonous acids,arylphosphonous acids (note publication of John R. Van WazePPhospherousand Its Compounds"), sulfuric acid, strong alkyland arylcarboxylicacids, particularly halogenated derivatives of these acids, and mixturesof such acids in an appropriate relationship of initial polymerizationand subsequent cure, as described. For example, sufficient strong acidmay be used to effect initial condensation polymerization withsubsequent cure, without addition of more acid catalystmaterial, oruse'of a weaker condensation catalyst initially, with addition of astronger catalyst for curing, or a combination of such catalysts asdesired. 1

Essentially, the condensable aromatic curing agent material, asindicated, is a polymethylol aromatic compound having the structuralformula onion DI H00 1' Hoc 1 cmoH CH|0H C Q -HOCH:

wherein X is selected from the group consisting of oxygen, sulfur,

i O l lalkytas -'-CH arylas and U,

and the like, including mixtures of the same, as disclosed in thecopending application for Resinous Curing System And Method" Ser. No.665,303 of Leroy J. Miller, and in which I am co-inventer. Theadditional ring substituents may be sterically non-interfering hydrogen,alkyl, aryl, alkaryl, aralkyl, alkoxy, aryloxy, partially halogenatedderivates thereof.

The above examples are illustrative of a preferred method of applicationof mixtures utilizing a typical and preferred type polyphenyleneprepolymer solution, others of which may be prepared by substitution ofaromatic polymethylol monomers and acid catalyst, or polymers thereof,and mixtures of the same, having incorporated therewith the solidsand/or other modified or modifying plastic resin-forming material, inthe manner as described, illustrated and embodied herein. As indicated,the curing agent is preferably prepared as a prepolymer, such as apolyoxyxylylene, derived from the above compounds by reaction with anacid, as herein indicated and described in the above application whichis included herein by reference thereto.

in further exemplification ofa new use for the soluble and fusiblearomatic polymers herein described, and also soluble and fusiblearomatic polyphenylene polymers of anthracene, naphthalene, phenanthreneand modifications thereof with biphenyl, terphenyl, quaterphenylcompounds, mixtures of the same and mixtures thereof with other aromaticmonomers, oligomers, or polymers of not more than aromatic rings, whichare curable with aromatic polymethylol and acid catalyst, polymethylolderivatives thereof, and aromatic polyfunctional sulfonyl halides, as1,3,5-benzenetrisulfonyl chloride, parabenzene disulfonyl chloride, 3, 4biphenyl disulfonyl chloride, sulfonyl bromides, sulfonyl fluorides, andthe like, (as described in my copending application entitled METHOD OFPREPARlNG THERMOSETTING PLASTICS AND PRQDUCT," Ser. No. 665,302, nowabandoned, included herein by reference thereto). Or mixtures of thepolyfunctional curing agents, and mixtures thereof with the polymethyloland acid catalyst combination may be used as curing systems with thepolyphenylene polymers; which polymers can be modified by, or providemodification of, synthetic or natural thermoplastic and thermallyunstable polymeric' material of the character obtained in thepreparation and synthesis of hycrocarbons including such materials aspitch plastics", coumarone polymers, indene polymers, polystyrene, coaltar pitch, earth and mineral asphalt and bituminous material, mixturesthereof, and the like, as shown by the followmg:

EXAMPLE 5 Polyphenylene (40 g., m.w. 1000, m.p. l60200C) and aromaticcoal tar pitch was dissolved in p-dioxane (150 ml.). To the hot solutionwas then added a solution of curing agent derived from 1,4xylyleneglycol(20 g.) p-toluenesulfonic acid monohydrate (6 g.) and chloroform (150ml.). The curing agent solution had been heated at reflux for 20 hourswhile removing water continuously before addition to the polyphenylenesolution. The combined polyphenylenexylyleneglycol solution was thenheated at 70C for 6 hours. It weighed 381 g. and contained 21 percentsolids when finished. This lacquer was found to be suitable as a varnishuseful on fiber reinforcements to be used in filament windingapplications.

EXAMPLE 6 A curing agent solution was prepared by reactingpxylyleneglycol (30 g.), p-toluenesulfonic acid hydrate (9 g.), andchloroform at reflux for 20 hours while stirring and removing watercontinuously. This solution was then added to a solution ofpolyphenylene (60 g., m.w. 1,000, m.p. l60200C), and aromatic coal tarpitch (30 g.), in trichloroethylene (180 ml.). The combined solution wasthen heated at reflux for 20 hours to yield 649 g. of lacquer containing18.5 percent solids.

EXAMPLE 7 A curing agent solution was prepared in telomer form fromrecrystalized (p-xylyleneglycol 50 g.), p-toluenesulfonic acid hydrate(16 g.) and chloroform by heating the stirred mixture at reflux for 20hours while removing water continuously. Chloroform was then removedunder vacuum while keeping the temperature below 50C. The solid telomerwas then redissolved in dioxane.

The above solution was then mixed with a solution of polyphenylene (60g., m.p. 140-l82C, C:H atom ratio 1.57, m.w. about 1,000), aromatic coaltar pitch (40 grams) and p-dioxane (200 ml.). The combined mixture wasthen heated at C for 3% hours to yield 826 g. of lacquer with 18 percentsolids content.

Otherwise, as above described, a combination of the polyphenylenematerial can be prepared with or without the inclusion of intractableand insoluble, or relatively inert material, and a polyfunctional curingagent with a modifying thermoplastic resinous material as illustrated bythe following:

EXAMPLE 8 A mixture of soluble polyphenylene material of a mean Crldatomic ratio on the order of 1.4 to 1.7 and in monomer and polymer form(about 20 grams) with 1,3,5-benzenetrisulfonyl chloride (about 10 grams)was dissolved in hot chloroform and an aromatic pitch plastic comprisedof a mixture of benzyl, phenyl or phenylene polymers was added (about 10grams) and the mixture heated for a period of about 5-10 hours at refluxtemperature (about 61C). This prepared solu tion, in lacquer form,served as an impregnate and coating composition and sealant. Uponheatsetting in a temperature range of about 275F to about 550 1 the solidsof the lacquer composition were converted or copolymerized to athermoset relatively insoluble state. Normally, the different curingagent polymer combinations will require their own reaction temperaturesand heat setting temperatures as is recognizable to those skilled in theart.

Further solutions of the above and similar and equivalent thermoplasticadditives as polystyrene and the like were prepared and utilized aslaminating impregments as exemplified in Example 2. In preparation ofthe soluble components, as a molding composition, the solvent wasremoved with care being taken not to complete copolymerization orsetting, of the solvent soluble polymers. The resoluble dried polymerswere ground to a relative powder form which was moldable, as is, with orwithout the addition and mixture of filler material as inertconventional material or synthetic fibers, ceramic material, metaloxides, and the like. For additional aid in effecting the initialreaction with retention of solubility, less of the curing agent materialmay be used and for the final curing reaction, more curing agent can beadded or mixture provided of the polymethylol and acid catalystcombination therewith.

When the combination of polymethylol and acid catalyst are added, it ispreferably in a prereacted or prepolymer form of XO Cl-l RCl-l o Xwherein R is one or more fused or unfused aromatic ring group or groupsderived from a characteristic formula HOCl-I RCH OH wherein R is thesame or different ring group. Two or more CH,OH groups may be on thesame or different ring structure and X is a combination of hydrogen andacid moiety minus the OH group or a combination of acid derivativesminus the OH group derived from an acid material as heretoforedescribed.

The above examples are illustrative of modifications of either or boththe fused and unfused aromatic ring compounds in combination with athermoplastic material and curing agent to provide new useful solubleand fusible thermosetting resin compositions convertible to thermostableresins. The substitution of components and solvents as enumeratedherein, temperature and times of reaction andcuring cycle will varydependent upon the particular mixture and end results desired by theoperator, as is now recognizable to those skilledin this art. As it willnow be recognized, the aromatic monomers forming the aromatic fused andunfused polyphenylene polymers may, less preferable, be mixed with thecuring agent material, in monomeric form, for effecting an in-situreaction of partial cure, preferably with retention of solubility andfusibility, for subsequent cure to a more heat resistant and thermallystable state. In either event, the mixtures, as herein provided areinterpolymerized to a partially cured fusible, soluble copolymer stateand finally to a more heat resistant cured copolymer state, as desired.The relative proportions of admixture of components are dependent uponthe relative end use results desired orrequired with respect to finalhardness, softness, tackyness, or flexibility of the relativelyplasticized aromatic polyphenylene or the increase in thermal stabilityof the thermoplastic material. Incorporated with the compositions hereinprovided may be inert inorganic or organic fillermaterial and mixturesthereof of a conventional character, including, for example, naturaland'synthetic rubber material, cellulosic material, synthetic fibermaterial, metal oxides, siliceous material and the like.

Having described the present embodiments of my discovery and improvementin the art, in-accordance with the constitutional grant and the PatentStatute, it will be made within the scope of this disclosure withoutdeparting from the spirit and embodiment thereof. The specificembodiments above described are given by way of examples illustrative ofmy invention, discovery, and improvement, which is to be limited only bythe terms of the claims.

What is claimed is: V

l. The method of preparing a modified curable resinous composite ofsoluble and fusible polyphenylene polymers having a mean carbonzhydrogenatomic ratio on the order of 1.4:1 to 1.7:1 and essentially soluble inhot to boiling halogenated benzene, p-dioxane, chloroform,tetrachloroethane, toluene, vtrichloroethane or trichloroethyleneheatedsolvent material and containing comparativelyintractable and infusiblepolyphenylene polymer solids which are substantially insoluble in thesaid heated solvent for said soluble and fusible curable polyphenylenepolymers comprising the steps of:

1. preparing a mixture of said soluble, fusible polyphenylene polymershaving a mean molecular weight on the order of about 500 to about 3,000,in combination with 2. a curing agent therefor selected from the groupconsisting of a combination of an aromatic polymethylol compound havingthe structural formula onion onion HOCH:

CHxOH wherein X is selected from the group consisting of oxygen, sulfur,

alkyl, aryl, and including such compounds having additional ringsubstituents of sterically non-interfering hydrogen, alkyl, aryl,alkaryl, aralkyl, alkoxy, aryloxy, and partially halogenated derivativesthereof, and mixtures of the same containing a heat reactivepolymerization affecting acid catalyst material selected from the groupconsisting of one or more of the aromatic sulfonic acids, phosphoricacid, alkylphosphonic acids, arylphosphonic acids, alkylphosphorousacids, arylphosphorous acids, sulfinic acid, alkyland arylcarboxylicacids, and halogenated derivatives of these acids, or a polyfunctionalaromatic sulfonyl halide, and mixtures of said curing agents which onheating effect copolymerization of said soluble and fusible polyphenylerie polymers with said aromatic polymethylol compound or with saidaromatic sulfonyl compound;

3. incorporating in said mixture polyphenylenepolymer solids which areinsoluble in said heated solvent;

4. blending said mixture of soluble and insoluble polymers, and 5.recovering a composite mixture of said soluble and fusible polyphenylenepolymers containing said insoluble polymer solids and curing agentcombination' coreactive and heat setting in a temperature range on theorder of 275 550F.

2. The method of claim 1, including the steps of preparing the mixturein a said hot solvent for said soluble polyphenylene polymers, partiallyreacting the said polymers and curing agent with retention of theirsolubility in saidsolvent, removingthe solvent without substantialfurther cure, and grinding the solids and uncured polymers to apowderform.

3 The method of claim 1, including the step of adding additional solubleor insoluble organic or inorganic modifying material-to said mixture.

4. The method of claim 2, including the steps of removing the saidsolvent from the said mixture, powdering the said solid, molding thesaid powder and heatcuring the mixture.

5. The method of claim 2 wherein the preparation in Step 1 and Step 2includes heating the mixture of soluble polymers of polyphenylene andcuring agent solution at reflux temperature and effecting reaction ofsaid hot solvent soluble polymers and curing agent with greaterhomogeneity for the insoluble polymers of Step 3.

6. The method of claim 1 wherein the said preparation includes the stepsof cooling the mixture of Steps lomer.

Po-wfio UNITED STATES PATENT OFFICE CERTIFICATE O CORRECTION Patent N3,758,630 Dated September 11, 17973 Inventor(s) Novrmaiil ilOW It iscertified'that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Cover page, [21] Appl. No. 194,779 should'read:

Appl. No. 104,779

Signed and sealed this --23r'dday of April 19%..

(SEAL) Attesc:

EDWARD M.FLETCHER,JR. C. MARSHALL DANN Attesting Officer Commissioner ofPatents

2. The method of claim 1, including the steps of preparing the mixturein a said hot solvent for said soluble polyphenylene polymers, partiallyreacting the said polymers and curing agent with retention of theirsolubility in said solvent, removing the solvent without substantialfurther cure, and grinding the solids and uncured polymers to a powderform.
 2. a curing agent therefor selected from the group consisting of acombination of an aromatic polymethylol compound having the structuralformula
 3. incorporating in said mixture polyphenylene polymer solidswhich are insoluble in said heated solvent;
 3. The method of claim 1,including the step of adding additional soluble or inSoluble organic orinorganic modifying material to said mixture.
 4. The method of claim 2,including the steps of removing the said solvent from the said mixture,powdering the said solid, molding the said powder and heat-curing themixture.
 4. blending said mixture of soluble and insoluble polymers, and5. recovering a composite mixture of said soluble and fusiblepolyphenylene polymers containing said insoluble polymer solids andcuring agent combination coreactive and heat setting in a temperaturerange on the order of 275* - 550*F.
 5. The method of claim 2 wherein thepreparation in Step 1 and Step 2 includes heating the mixture of solublepolymers of polyphenylene and curing agent solution at refluxtemperature and effecting reaction of said hot solvent soluble polymersand curing agent with greater homogeneity for the insoluble polymers ofStep
 3. 6. The method of claim 1 wherein the said preparation includesthe steps of cooling the mixture of Steps 1, 2 and 3, and blending themixture of infusible polymer solids therewith in a high shear blender.7. The method of claim 1 wherein the said insoluble polyphenylenepolymers are essentially parapolyphenylene.
 8. The method of claim 1wherein the soluble polyphenylene polymers of Step 1 have a meanmolecular weight of about 500 to about 2,000 and are soluble in a saidhot halogenated hydrocarbon solvent.
 9. The method of claim 1 whereinthe curing agent comprises a xylylene glycol-p-toluenesulfonic acidtelomer.